For which of the following scenarios are the Amazon Elastic Compute Cloud (Amazon EC2) Spot instances most appropriate?

Answer options:

A.Workloads that are only run in the morning and stopped at night
B.Workloads where the availability of the Amazon EC2 instances can be flexible
C.Workloads that need to run for long periods of time without interruption
D.Workloads that are critical and need Amazon EC2 instances with termination protection

Answer – B
The AWS documentation mentions the following.
Spot Instances are a cost-effective choice if you can be flexible about when your applications run and if your applications can be interrupted. For example, Spot Instances are well-suited for data analysis, batch jobs, background processing, and optional tasks.
For more information on AWS Spot Instances, please refer to the below URL:
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-spot-instances.html
Options A, C, and D are incorrect. Since spot instances can be terminated by Amazon depending on market prices, they cannot be guaranteed to run during a specific period of time. It will impact the workloads especially when they are critical.